Robotics has come to denote the implementation of human like activities by machines. This includes robots which have the capability of handling materials analogous to handling by the human appendages, including arms and hands. The robot can be controlled to act according to the operator's direction or by the use of a pre-established program to carry out many mechanical functions that substitute for a human, particularly in environments which are hostile to humans. Outer space is one such hostile environment; extremely cold and in vacuum in which a human could not survive without suitable protection.
On Earth hostile environments also exist where a person would be subjected to the ill effects of extreme heat or cold, nuclear radiation, toxic chemical waste, etc. Deep-sea underwater exploration also involves working in an extremely hostile environment, where robotic devices could perform many of the tasks performed by humans in a bathysphere. Even more importantly, the robot can carry out manipulative tasks repeatedly and accurately without tiring. A robotic manipulator forms part of the Robot and performs the manipulative functions.
In the copending application of S. K. Ubhayakar, Ser. No. 156,256, filed Feb. 16, 1988, for an invention entitled Flexidigit Robotic Manipulator, a novel positioning such as a robotic arm or finger member, contains a plurality of substantially identical relatively rigid disks or platforms that define multiple joints in the arm structure. The platforms are spaced and angularly oriented relative to one another by mechanical coupling and positioning means carried by and within the boundary of the platforms, such means being selectively individually operated or controlled. The coupling means serve also as a stabilizer to prevent sideways movement of any one platform with respect to an adjacent platform, thereby insuring rigidity of the device at any assumed shape, while allowing the flexibility of changing the shape. In an additional aspect, the positioning device is ensleeved by a sheath of flexible material that serves as a skin protecting the internal components from external contaminants, such as dust, radiation, corrosive chemicals, and the like. A more specific aspect of the invention is a feature in which the positioning and coupling means includes actuator devices, such as solenoids, motors, fluidic pneumatic cylinders, shape memory alloys, piezoelectric materials or even strings, at each of three corresponding locations on adjacent platforms; and further contains a series of three stabilizer rods, containing ball and socket joints intermediate their length, with the rods hingedly connected at their ends to adjacent platforms for precluding relative sideways movement of those respective platforms, thereby allowing the arm to be structurally rigid at any pre-set shape.
The unique and simple nature of the structure disclosed in the Ubhayakar application allows greater freedom to the designer. Portability has rarely appeared in connection with industrial robots whose function is to stand and perform repetitive tasks on an assembly line. As publicized recently small robots had the ability to wheel around to different locations in a convention hall or the like and raise an arm to serve one a drink as a possible elemental example, but one which is not capable of performing intricate construction work.
In the prior Ubhayakar structure each disk or platform of the robotic arm contained a central opening through which power cables originating in the base extended. Each section of the arm contained its own actuators. Power was furnished to each actuator by a set of electrical wires which extended from the base through the central opening to the actuators. Since these wires were separate circuits as the number of sections to the arm grew the number, weight and bulk of the wiring that needed to be squeezed through the central openings particularly the openings nearest the base grew. The present invention provides the power without the need for the limiting bulk of wires and substantially reduces the number of wires needed to control the arm, even in arms consisting of large numbers of sections.
An object of the present invention is to provide a robotic arm that is portable and easily detaches and attaches to different positions of a support structure. A further object is to provide an assembly or construction system that incorporates positionable robotic arms in which the arms obtain operating energy as well as support though means of the structure that is assembled by the robotic arms. A still further object is to provide a "smart" arm; that is, one which is totally self-contained and one which may be controlled remotely by means of radio communications or other wireless techniques, and/or which can perform at least one manipulative function on its own so to speak. A still further object is to provide a completely self-contained robot arm having "hands" at opposed ends of the arm that contains several "fingers". An advantage of that structure is that one can attach to a surface and allow positioning of other external objects gripped by the remaining hand, a feat that is specifically useful in assembling unique structures. A still additional object is to provide a new assembly technique that incorporates the use of detachable, multi-jointed, robotic positioning members, such as robotic arms and fingers. Multiple controlled arms may be positioned on various portions of structure, assemble additional structure, and then move on to a new location in an almost super human fashion to provide a decided advantage in assembling structures in environments that are hostile to humans.
An additional object of the invention is to provide a power distribution system for a robotic arm that eliminates costly, bulky and heavy electrical wires of the kind presented in the robotic arm structure described in the cited Ubhayakar patent application.